What is CNC machining? Process, material, application, process, surface treatment

 What is CNC machining? Complete and relevant knowledge

Ⅰ  Overview of CNC machining

CNC machining is a process of operating machine tools through computer numerical control systems. This machining method can be automatically processed through pre-programming, reducing human operating errors and improving efficiency.

In CNC machining, the cutting tool is processed according to a pre-programmed path and operating instructions. This processing method has high accuracy, good repeatability, high processing efficiency, and is suitable for mass production. Due to its superior performance advantages, CNC machining has been more and more widely used and developed in modern manufacturing industry. When using CNC machine tools, first of all, the geometric information and process information of the machined parts drawings must be written into the processing program with the specified code and format; Then the processing program is input to the numerical control device, according to the requirements of the program, through the numerical control system information processing, distribution, so that the coordinates move a number of small displacement, to achieve the relative movement of the tool and the workpiece, to complete the processing of parts.

CNC machining can be applied to a variety of materials, including metal, plastic, wood, etc., and can be used to manufacture a variety of products, such as auto parts, industrial machinery, aerospace parts, etc.

Ⅱ  CNC machining development history

After World War II, most of the production of the manufacturing industry relies on manual operation, workers read drawings, manual operation of machine tools to process parts, with this way to produce products, high cost, low efficiency, quality is not guaranteed. In the late 1940s, an engineer in the United States, John Parsons, conceived of a way to punch holes in a cardboard card to represent the geometry of the parts that need to be processed, using a hard card to control the action of the machine tool, at that time, it was just an idea. In 1948, Parsons showed his idea to the United States Air Force, the United States Air Force after seeing, expressed great interest, because the United States Air Force is looking for an advanced processing method, hoping to solve the processing problem of aircraft appearance template, due to the complex shape of the template, high precision requirements, general equipment is difficult to adapt. The United States Air Force immediately commissioned and sponsored the United States Massachusetts Institute of Technology (MIT) to conduct research, the development of this cardboard to control the machine tool, and finally in 1952, MIT and Parsons Company cooperation, successfully developed the first demonstration machine, by 1960 more simple and economical point control drilling machine, And linear control CNC milling machine has been the rapid development of CNC machine tools in the manufacturing sector has gradually been promoted.

The history of CNC machining has been more than half a century, the NC system has also developed from the earliest analog signal circuit control to an extremely complex integrated processing system, and the programming method has also developed into an intelligent and powerful CAD/CAM integrated system.

Ⅲ  The workflow of CNC machining

1 Design

The first critical step in CNC machining requires the use of software applications such as CAD, CAM and CAE. Engineers and designers rely on these tools to design parts and products and then conduct a design for manufacturability (DFM) evaluation, a process that is critical. It ensures that the design is optimized to maximize efficiency and reduce costs, while working within the constraints of existing technology.

2 Preparation Phase

According to the drawings of the machined parts, determine the relevant processing data (tool track coordinates, machining cutting, tool size information, etc.), and select other auxiliary information according to the process plan, the selected fixture, the type of the tool, etc.

3 Programming Phase

According to the machining process information, the NC machining program (the description of the machining process) is written in the language that can be recognized by the CNC system of the machine tool and the program list is written. CNC machine programming mainly involves communicating with the machine using G code and M code. These codes are generated by the CAM package and serve as a guide to the cutting tool path in CNC operation.

4 Processing stages

When the program is executed, the machine tool numerical control system (cnc) converts the processing program into the action instructions that drive the moving parts, drives the timely movement of the moving parts under the unified coordination of the system, and automatically completes the processing of the workpiece.

Ⅳ  Common CNC machining types

1 CNC milling

CNC milling is a reductive manufacturing process that uses cutting tools mounted on a rotating spindle to selectively remove material from the original substrate. The workpiece is rigidly mounted on a work table that can be moved or rotated on different planes, so the tool can work at multiple angles, easily producing parts that require good flatness and precise complex surfaces.

One of the main features of a CNC milling machine is its ability to perform intermittent cutting using multiple machine steps, which allows for the efficient creation of complex geometric shapes. The technology has evolved to include 3, 4 and 5-axis milling machines:

3-axis milling: Movement along the X, Y, and Z axes enables basic operations such as drilling and planing. This method is ideal for projects that require simple shapes and is popular because of its simplicity. However, it is limited in its ability to create complex geometrics, making it less suitable for complex designs.

4-axis milling: Add a rotating shaft for more complex operations than 3-axis milling. This method is ideal for angular cutting and more complex shapes, extending the capabilities of CNC machining. It is particularly useful for parts that require additional precision that cannot be provided by 3-axis milling machines.

5-axis milling: The pinnacle of CNC milling, this type of machining can move along five axes, allowing for extreme precision and complexity. In the high-precision industry, it is invaluable for creating complex shapes with tight tolerances. This approach simplifies production by reducing the need for multiple setups, ensuring efficiency and accuracy.

2 CNC turning

CNC turning is a reduction manufacturing process in which a cylindrical material is fixed to a tray on a spindle and rotated while a cutting tool is fed into a bar to remove material to create a part or product. It is an efficient processing process, mainly used to form cylindrical workpieces, of course, can also handle square or hexagonal raw materials. CNC turning has the characteristics of low cost, high efficiency, high quality and high precision, which is liked by most customers.

Type of turning machine:

CNC lathe: good at precision turning operation, very suitable for machining high-precision cylindrical parts.

CNC Turning Center: It combines turning with additional functions such as milling and drilling. This multitasking capability allows complex parts to be produced in a single setup, resulting in increased efficiency and accuracy.

3 CNC drilling

CNC drilling machine is mainly used for drilling, reaming, chamfering and other processing. The advantage of CNC drilling is that the drilling speed is fast, the operation is simple and the function is powerful.

Mainly used in automotive, mold, shipbuilding, aerospace, construction machinery industries, especially for some hardware parts with multiple holes need to be processed especially suitable.

CNC milling machine is developed on the basis of the general milling machine, the processing technology of the two is basically the same, the structure is also somewhat similar, but the CNC milling machine is an automatic processing machine controlled by the program, so its structure is also very different from the ordinary milling machine.

CNC milling machine features:

• The adaptability and flexibility of parts processing are strong, and the parts with particularly complex contour shapes or difficult to control size can be processed.

• High machining precision, stable and reliable quality.

• High production efficiency

• It can process parts that need to be processed in multiple processes after one clamping and positioning

  
  

5 Electrosparking

An electrical discharge machine (EDM) is a manufacturing process that uses electrical discharge to erode materials and produce complex shapes and geometries. The process works by creating a spark between the electrode and the workpiece, immersing the workpiece in a dielectric solution that isolates electrical energy and allows for precise control of the spark. The spark discharge vaporizes the workpiece and removes the overhaul material to obtain the desired shape.

There are two main types of EDM: EDM forming settler and EDM wire cutting machine.

6 CNC plasma cutting

Plasma arc cutting is a processing method that uses the heat of high temperature plasma arc to melt (and evaporate) the metal at the workpiece incision, and uses the momentum of high speed plasma to remove the molten metal to form the incision.

This technology is known for its versatility and can seamlessly cut thin and thick materials with high efficiency, high schedule and economy, and is an important tool in modern manufacturing.

7 CNC laser cutting

CNC laser cutting is to focus the laser beam on the surface of the workpiece, so that the area of the workpiece is illuminated by the spot instantly melted and vaporized, and automatic cutting is achieved by moving the position of the spot irradiation through the computer-controlled CNC mechanical system. The compressed gas coaxial with the laser beam is used to blow away the melted material, and the laser beam and the material move relative to each other along a certain track, so as to form a certain shape slit. It is a set of laser technology, numerical control technology, precision machinery technology in one of the high-tech.

CNC laser cutting features: high precision, narrow slit, smooth cutting surface, fast speed, no damage to the workpiece, not affected by the material and shape, cost saving.

8 CNC engraving

CNC engraving from the processing principle is a combination of drilling and milling processing, through the CAM software design of any pattern, font, three-dimensional path for computer computing processing path.

It can be applied to all kinds of flat materials for cutting, 2D engraving, 3D engraving. Main functions and advantages: powerful, a multi-purpose machine, whether it is the production of bronze, stainless steel plate, titanium gold medal, aluminum plate and other metal surface engraving, engraving pattern and art graphic crafts, can be easily done.

Ⅴ  Common CNC materials

Ⅵ  Common CNC surface finishing

Ⅶ  Advantages and disadvantages of CNC machining

1 Advantages:

• Produce parts with tight tolerances and excellent repeatability

• High-speed operation to provide parts production efficiency

• With flexibility, from simple to complex design, with effective programming and correct machining methods.

• It is cost-effective and reduces the production cost of enterprises

• Higher security

• Automate production and reduce production management

2 Disadvantages

• CNC machine tools are expensive, some enterprises can not afford

• Experienced engineers and operators are required

Ⅷ  CNC machining applications

Ⅸ  Ending

CNC machining is the cornerstone of modern manufacturing, which improves production efficiency and product quality, and reduces the impact of human factors on the processing process. Secondly, CNC machining can achieve automated production, reducing labor costs and production cycles. In addition, CNC machining has the advantage of strong flexibility, and can quickly adjust processing procedures and parameters according to needs to adapt to changes in market demand.

Interested in experiencing first-class CNC machining services? Please contact us immediately, we will give you the best quality service and products.We will continue to update relevant articles on the website, if you are interested, you can come to our website to continue reading.

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